@article{Maciejewski:2001,
  author  = "A. Maciejewski and J. Moulin-Ollagnier and A. Nowicki",
  title   = "Simple quadratic derivations in two variables",
  journal = "Communications in Algebra",
  volume  = "Vol. 29",
  number  = "no 11",
  pages   = "5095--5113",
  year    = "2001",
}